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Birdhouses provide both nesting places for birds and sources of enjoyment for many people. If you are building a birdhouse, you have the choice to focus on adding beauty to your yard or providing a functional space for birds. But, as far as the finish goes, can you safely varnish a birdhouse and provide a non-toxic resting place?
Yes, there are non-toxic varnishes manufactured that are perfect for finishing birdhouses. Find a varnish labeled as non-toxic, environmentally friendly, or made from natural materials. After finishing, allow the birdhouse to off-gas before it is ready for habitation.
In this article, we will offer a quick overview of birdhouse construction, explore the types of finishes to use, and how to make the safest choices when selecting a finish.
For our readers who are looking for a non-toxic varnish option here is a perfect one by DecoArt, available on Amazon, and an environmentally friendly varnish for birdhouse use.
The Basics of Building a Birdhouse
The goal of a birdhouse is to provide a safe place for birds to nest or live. If you are building your own house, there are many choices for the style, construction materials, and finishing touches. It is helpful to have some necessary details before considering adding varnish or another finish to the birdhouse.
Most birders prefer wood for material to build a birdhouse because it offers better protection against the elements. Ensure the wood is not treated with any harmful chemicals that could be toxic to birds. You also need to make sure the materials you use to paint and finish your birdhouse are non-toxic (source).
Cedar and redwood are two solid choices for birdhouse material because they are naturally weather-resistant and do not require a finish. For more information on the specific materials needed to build quality birdhouses, consult the article, “What Materials Do You Need to Build a Birdhouse?”
Varnishes and Other Finishes
Especially if you have the right wood, finishes are largely a matter of personal preference, as long as the chosen materials are safe for birds. Give birds’ sensitivities to toxic chemicals, there are many items to look for and think about once you’ve decided to enhance your birdhouse’s outward appearance.
The biggest concern when building a birdhouse is how to make the home as safe as possible for its occupants. Knowing the types of finishes and how to make the best choices for a final coating will help protect both the birds and their surroundings.
Varnish is one type of finish to use on a completed birdhouse, providing an additional layer of protection against the elements while also extending the paint job’s life by applying it over stains and paints.
It offers a transparent layer that allows the underlying wood grain or paint color to show through.
There are numerous varnish types, but they all generally contain the same components: drying oil, resin, thinner, and resin. All varnishes will undergo a process of drying and hardening, but the process itself can differ.
You will want to look for the same characteristics in varnish as with paints. Make sure you purchase a finishing coat that is labeled non-toxic and is as natural as possible.
Products that contain a small amount of volatile organic compounds are better for the environment because they contribute so little to air pollution. These compounds can also be unhealthy for birds, so it is beneficial to avoid them altogether.
Varnish is a solid finishing coat choice for birdhouses or any piece of wood kept outdoors. It handles extreme temperatures well and protects the wood from potentially harmful factors such as saltwater or UV rays. It is long-lasting and, as long as it is labeled non-toxic, a great choice for a birdhouse topcoat.
Oil finishes contain drying oils derived from various nuts and seeds, and there are plenty of non-toxic options from which to choose. However, keep in mind that the oil finishes will show wear and tear much more than other finishes.
The most popular ones used are linseed oil and tung oil. These both harden the surface of the birdhouse while also curing the wood. Unlike linseed oil, tung oil creates a barrier to protect the birdhouse from water and chemical damage.
Shellac is a natural product, safe for both plants and animals, that protects against stains and water. Processors derive it from Lac beetles’ secretions, which is dried and mixed with alcohol to create the finish.
The finished effect of shellac is a glossy topcoat that brings out the paint or wood’s base color. While shellac is an excellent choice for birdhouses because of its natural components and high sheen, it is susceptible to damage from scratches and heat.
While this type of varnish was originally developed for use on ships to protect them from the saltwater and weather. Its elasticity works to keep the wood and paint safe from the weather. Marine varnish also has the quality of being water-resistant, a valuable quality for the birds residing in the houses.
The class of water-based finishes has low solvent levels making them an excellent choice for surfaces that animals encounter. They create a shiny surface which, unlike oil-based finishes and shellac, repels both water and stains.
Polyurethane can be either oil or water-based. No matter which one you choose, your birdhouse is sure to have a durable and waterproof topcoat that will look good for a long time. However, it does not protect against UV rays long-term, so additional coats must be applied to keep the wood underneath in top condition.
The oil-based version has a slower dry time and must be sanded between coats to create a grippy texture for the next layer. However, it gives a warm glow to the surface. Water-based polyurethane dries quickly and has a clearer finish than the oil-based version. It is also much easier to clean.
What to Look for in a Finish
You will want to find a finish that is non-toxic for birds and other animals, safe for the environment, and durable. Along with these factors, you will also want to make sure the finish you choose to use keeps the birdhouse protected from the weather and pests.
Clear finishes will allow the paint color to shine through, which is preferable to most people. If you choose to go this route, attempt to find a safe product for animals that also helps absorb UV rays.
However, you would do well to avoid products that leave a high gloss, which can startle birds. A matte finish is better suited for birdhouses (source).
Painting a Birdhouse
There’s no rule requiring you to paint your birdhouse. Some birds prefer a more weathered and natural feel, without the feel or smell of a painted home. However, painted birdhouses appeal to a wide range of birds.
Take care to avoid dark colors, which will hold in more heat. Using earth tones will help the birdhouse blend into the environment, which works well because it helps to keep the birds safe from predators.
If the birdhouse happens to be in a flower garden, choosing paint colors that match this type of surrounding will be better for camouflaging. If you are trying to attract a specific type of bird, you can research which colors are most appealing to the desired species.
More decorative choices can range from adorning the outer walls of a birdhouse with flamboyant colors to painting a replica of your own home. As long as the paint is non-toxic and free from harmful chemicals, you have a variety of color choices and designs to choose from.
Not only can painting a birdhouse add to the appeal for both birds and humans, but it can also add to the structure’s durability. Paint can make birdhouses more weatherproof and long-lasting, which are beneficial characteristics of a structure.
If the birdhouse is not completely sealed, it may fall victim to the elements and not last as long as expected. The interior of a birdhouse can stay dry, and the wood protected by closing up any small cracks or holes in the walls and floor.
Rain and snow can destroy a birdhouse from the inside, while expansion from summer heat can worsen the cracks.
A new paint job can also do wonders to freshen up older birdhouses and extend the life of the homes. As you are cleaning out the birdhouse, be sure to check for any chipped paint. If swallowed, paint chips can be very harmful to birds. You will need to repaint before the birdhouse is safe for new residents.
Additionally, if you choose to move homes or the location of the birdhouse, you might decide to change the paint color to match the new surroundings.
As long as you let the paint dry and allow substantial time for the fumes to dissipate, your painted birdhouse should be ready to go in less than a week.
Nowadays, most paints are made with compounds that have helped increase durability, lower costs, and decrease the harm to the environment.
Natural paints are made from raw ingredients and organic minerals. They can be water-based or oil-based, the latter usually including a light fragrance. Because these paints are natural, they also offer the benefit of being safest for the environment, including animals.
If looking for other paint options, keep in mind that water-based paint will contain little to no harmful ingredients. Even though they still initially give off an odor, their harmful emission rate is much lower than their oil-based counterparts.
For birdhouses, natural paints that are labeled non-toxic are the safest options. They offer the least amount of potential harm to birds or their environment. If you paint the birdhouse in the fall or winter, the paint will have ample time to dry and the fumes to be gone before the next season (source).
Building your own birdhouse is a great way to expand your creativity while providing a cozy space for birds to nest and live. You may choose to leave your birdhouse natural, or go the route of varnishing and finishing the outside.
If you decide to use paint and a top coat, you will need to choose what works best for the birds in your area. Materials should be free from harmful chemicals while still providing protection from the elements. By making these choices, you will keep your feathered residents safe and secure.
Many species of birds have been driven away from their homes due to habitat loss, so the addition of a birdhouse can help bring indigenous birds back to the area.